A. Field of the Invention
The present invention relates generally to a process to examine at least one object, whereby properties of the object are detected by various measurements within a spatial[-] frequency space formed by spatial frequencies. Preferably, the various measurements take place at different times. The present invention may be used to analyze the properties of various objects, such as for example, any object that may be imaged, any object typically measured using magnetic resonance imaging or nuclear magnetic resonance techniques, etc.
B. Description of the Related Art
Examinations of the spatial[-] frequency space are employed in a wide array of technical fields. Since pulse spaces correspond to spatial[-] frequency spaces, the term xe2x80x9cspatial frequency spacexe2x80x9d also encompasses pulse spaces. [The designation spatial-frequency space serves to clarify the fact that the invention also relates to a process in which no pulse transmission occurs.] A known problem encountered when imaging spatial[-] frequency spaces is that a very long measuring time is needed when a high local resolution is combined with a high spatial frequency resolution.
A keyhole process for solving this problem is known. In this process, a high-resolution image involving the detection of the entire spatial[-] frequency space is determined at least for one point in time. In one or more measuring steps, a central area of the spatial[-] frequency space is imaged that determines the contrast of the reconstructed image. Subsequently, the high-resolution image is mathematically linked to the recorded image(s) of the central areas of the spatial[-] frequency space in such a way that a high-resolution image having a contrast that corresponds to the point in time of the recording is determined for the other time or times.
This known process has the disadvantage that contrast changes between consecutive measurements can only be determined if they have a sufficiently large spatial extension. This disadvantage is particularly detrimental when functional parameters of the object are being detected. Thus, for instance, in functional magnetic resonance imaging, there is a need for parameters that influence nuclear magnetic resonance signals to be detected with the highest possible spatial resolution.
Thus, there is a need in the art for a process to examine the properties of an object within a spatial frequency space, especially the functional parameters of the object, that overcomes the problems of the related art.
The present invention [is based on the objective of creating] solves the problems of the related art by providing a process [with which it is possible to detect] for examining an object that enables detection of a change in the functional parameters of the object when the spatial areas affected by the change are relatively small. The process of the present invention occurs in the spatial frequency space. That is, no pulse transmission occurs in the process of the present invention.
More specifically, the process of the present invention solves the problems of the related art by taking various measurements in at least one shared area of the spatial frequency space and, additionally, in areas of the spatial frequency space that are different from each other. Preferably, the measurements detect the spatial frequency space in images taken at different times. In particular, the process of the present invention provides for examining areas of the spatial frequency space at rates of occurrence that differ from each other. More preferably, the process of the present invention provides for examining areas of the spatial frequency space at three or more different rates of occurrence for detecting areas.
Preferably, at least one, for example, centrally located area of the spatial frequency space is detected in several measurements while other areas are not detected at all, or are only detected in a single measuring procedure. Preferably the process is carried out in such a way that the overlapping areas cover a central region of the spatial frequency space.
In one aspect of the process of the present invention, the additional, but preferably not central, areas in the spatial frequency space are at a distance from each other that is greater than their spatial frequency extension in the direction of this distance. Preferably, the process is carried out in such a way that the other areas of the spatial frequency space extend, at least partially, parallel to each other. More preferably the disjunctive elements of the individual sets extend, at least partially, parallel to each other in the spatial frequency space.
In another aspect of the process of the present invention, the measurements are carried out in such a way that a cycle is formed in which at least some of the areas of the spatial frequency space that differ from each other are once again detected in additional measurements. In still another aspect of the process of the present invention, the detected areas that form a disjunctive set in at least one measurement.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
